fem_create_analysis · FreeCAD MCP: Risk & Policy

WHAT IT DOES

What fem_create_analysis does on FreeCAD MCP

AI agents use fem_create_analysis to create or update resources in FreeCAD MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your FreeCAD MCP environment.

WHY IT NEEDS A POLICY

Why fem_create_analysis needs a policy

This tool creates a new analysis object (reversible Write operation) within FreeCAD's modeling environment. It does not execute analysis (which would be Execute), delete data (Destructive), or affect financial systems. The empty description lowers confidence slightly, but the naming pattern and context of structural analysis tools on a CAD server clearly indicate it creates/initializes analysis configurations.

From the tool's definition Tool name 'fem_create_analysis' indicates creation of a finite element method (FEM) analysis object. Sibling tools like 'bim_create_column', 'bim_create_wall', etc. are Create operations that modify CAD models.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

fem_create_analysis Rate-limited

fem_create_analysis stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "fem_create_analysis": {
      "limits": [
        {
          "counter": "fem_create_analysis_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches FreeCAD MCP, so you can run agents against it safely.

FAQ

Questions about fem_create_analysis

What does the fem_create_analysis tool do? +

fem_create_analysis. It is categorised as a Write tool in the FreeCAD MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on fem_create_analysis? +

Register the FreeCAD MCP server in PolicyLayer and add a rule for fem_create_analysis: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches FreeCAD MCP. Nothing to install.

What risk level is fem_create_analysis? +

fem_create_analysis is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit fem_create_analysis? +

Yes. Add a rate_limit block to the fem_create_analysis rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block fem_create_analysis completely? +

Set action: deny in the PolicyLayer policy for fem_create_analysis. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides fem_create_analysis? +

fem_create_analysis is provided by the FreeCAD MCP server (sandraschi/freecad-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.